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STMicroelectronics |
® 74VHC240
OCTAL BUS BUFFER
WITH 3 STATE OUTPUTS (INVERTED)
s HIGH SPEED: tPD = 3.6 ns (TYP.) at VCC = 5V
s LOW POWER DISSIPATION:
ICC = 4 µA (MAX.) at TA = 25 oC
s HIGH NOISE IMMUNITY:
VNIH = VNIL = 28% VCC (MIN.)
s POWER DOWN PROTECTION ON INPUTS
s SYMMETRICAL OUTPUT IMPEDANCE:
|IOH| = IOL = 8 mA (MIN)
s BALANCED PROPAGATION DELAYS:
tPLH ≅ tPHL
s OPERATING VOLTAGE RANGE:
VCC (OPR) = 2V to 5.5V
s PIN AND FUNCTION COMPATIBLE WITH
74 SERIES 240
s IMPROVED LATCH-UP IMMUNITY
s LOW NOISE: VOLP = 0.9V (Max.)
DESCRIPTION
The 74VHC240 is an advanced high-speed
CMOS OCTAL BUS BUFFER (3-STATE)
fabricated with sub-micron silicon gate and
double-layer metal wiring C2MOS technology.
G output enable governs four BUS BUFFERs.
M
(Micro Package)
T
(TSSOP Package)
ORDER CODES :
74VHC240M
74VHC240T
This device is designed to be used with 3 state
memory address drivers, etc.
Power down protection is provided on all inputs
and 0 to 7V can be accepted on inputs with no
regard to the supply voltage. This device can be
used to interface 5V to 3V.
All inputs and outputs are equipped with
protection circuits against static discharge, giving
them 2KV ESD immunity and transient excess
voltage.
PIN CONNECTION AND IEC LOGIC SYMBOLS
June 1999
1/8
74VHC240
INPUT EQUIVALENT CIRCUIT
PIN DESCRIPTION
PIN No SYMBOL NAME AND FUNCT ION
1 1G Output Enable Input
2, 4,6, 8 1A1 to 1A4 Data Inputs
9, 7,5, 3 2Y1 to 2Y4 Data Outputs
11, 13, 15, 17 2A1 to 2A4 Data Inputs
18, 16, 14, 12 1Y1 to 1Y4 Data Outputs
19 2G Output Enable Input
10 GND Ground (0V)
20 VCC Positive Supply Voltage
TRUTH TABLE
X:”H” or ”L”
Z: High impedance
G
L
L
H
INPUT
An
L
H
X
OUTPUT
Yn
H
L
Z
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Value
Unit
VCC Supply Voltage
-0.5 to +7.0
V
VI DC Input Voltage
-0.5 to +7.0
V
VO DC Output Voltage
-0.5 to VCC + 0.5
V
IIK DC Input Diode Current
- 20 mA
IOK DC Output Diode Current
± 20 mA
IO DC Output Current
± 25 mA
ICC orIGND DC VCC or Ground Current
± 75 mA
Tstg Storage Temperature
-65 to +150
oC
TL Lead Temperature (10 sec)
300 oC
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is not implied.
RECOMMENDED OPERATING CONDITIONS
Symbol
Parameter
VCC Supply Voltage
VI Input Voltage
VO Output Voltage
Top Operating Temperature
dt/dv Input Rise and Fall Time (see note 1) (VCC = 3.3 ± 0.3V)
(V CC = 5.0 ± 0.5V)
1) VIN from 30% to70%of VCC
Valu e
2.0 to 5.5
0 to 5.5
0 to VCC
-40 to +85
0 to 100
0 to 20
Unit
V
V
V
oC
ns/V
ns/V
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